Biological processes are captured in Reactome by identifying the molecules (DNA, RNA, protein, small molecules) involved in them and describing the details of their interactions. From this molecular viewpoint, human disease pathways have three mechanistic causes: the inclusion of microbially-expressed proteins, altered functions of human proteins, or changed expression levels of otherwise functionally
Last changed: 2014-11-21 19:49:01

Metabolic processes in human cells generate energy through the oxidation of molecules consumed in the diet and mediate the synthesis of diverse essential molecules not taken in the diet as well as the inactivation and elimination of toxic ones generated endogenously or present in the extracellular environment. The processes of energy metabolism can be classified into two groups according to whether the
Last changed: 2014-11-21 19:49:01

Defective transcobalamin II (produced by the TCN2 gene) results in TCN2 deficiency (MIM:275350), an autosomal recessive disorder with early-onset in infancy characterized by failure to thrive, megaloblastic anemia, and pancytopenia. If left untreated, the disorder can result in mental retardation and neurologic abnormalities (Haberle et al. 2009)
Last changed: 2014-11-21 19:49:01

Defects in MMACHC cause methylmalonic aciduria and homocystinuria type cblC (MMAHCC; MIM:277400). MMAHCC is the most common disorder of cobalamin metabolism and is characterized by decreased levels of the coenzymes adenosylcobalamin (AdoCbl) and methylcobalamin (MeCbl). Affected individuals may have developmental, haematologic, neurologic, metabolic, ophthalmologic, and dermatologic clinical findings (
Last changed: 2014-11-21 19:49:01